Decoder: Fixed DoS in header decode when no PPS is present
When the input does not contain PPS and decoder is in header decode
mode, decoder was entering an infinite loop.
Bug: 33621215
(cherry picked from commit 33e1b190d6db09bd72a9f0f51acef4b14eabd6ff)
(cherry picked from commit 2cd2f7a33535f29c87a1952e0d4b43a80b6f1f3c)